In general, a dialysis apparatus serving as a blood purification apparatus intended for dialysis treatment is provided with tubes, such as a dialysate introduction line and a dialysate drain line, for introducing dialysate into a dialyzer (a blood purification device) connected to a blood circuit and for discharging the dialysate containing waste products resulting from the dialysis from the dialyzer. The dialysate introduction line and the dialysate drain line are connected at the distal ends thereof to a dialysate inlet and a dialysate outlet, respectively, of the dialyzer. Furthermore, the dialysate introduction line is connected at the proximal end thereof to a dialysate-supplying device. Thus, the dialysate is allowed to be supplied to the dialyzer.
In such a blood purification apparatus, the tubes such as the dialysate introduction line and the dialysate drain line are disinfected by washing prior to the dialysis treatment. In recent years, a hot-water-disinfection process in which hot water (with citric acid) is used as a washing-and-disinfection solution has been becoming popular. As disclosed by PTL 1, for example, such a known blood purification apparatus includes a circulation tube for forming a circulation flow route that allows liquid (washing water) to circulate in the hot-water-disinfection process, a heater (a heating device) capable of heating the liquid that circulates through the circulation flow route and generating hot water that is at a temperature required for hot-water disinfection, and a thermistor (a temperature-measuring device) capable of measuring the temperature of the liquid heated by the heater. The tubes are disinfected with hot water by causing the hot water at a predetermined temperature to circulate through the circulation flow route for a period of time required for hot-water disinfection.
PTL 1: Japanese Unexamined Patent Application Publication No. 2014-097197
The above known blood purification apparatus has the following problem.
The hot-water disinfection of tubes greatly depends on environmental conditions at the time of the hot-water-disinfection process. Therefore, the hot-water-disinfection time and so forth are set such that a satisfactory level of disinfection effect can be obtained even under the worst environmental conditions. That is, assuming that environmental conditions, such as the heating function of the heater (the power-source voltage); the supply water temperature; and the ambient temperature, are all at the worst levels in terms of generating hot water suitable for hot-water disinfection, a long hot-water-disinfection time estimated for the worst conditions is set so that a satisfactory level of hot-water-disinfection effect is guaranteed.
However, the hot-water-disinfection time that is set as described above tends to be greatly different from the hot-water-disinfection time that is required under normal environmental conditions. Therefore, the hot-water-disinfection time thus set tends to be excessively long. That is, in the known technique, hot-water disinfection cannot be performed efficiently, which may increase the power consumption and the heat stress given to components such as filters provided to the tubes. Hence, to make the hot-water-disinfection process more efficient, the hot-water-disinfection time needs to be optimized with consideration for environmental conditions.